Cesium is a chemical element with the symbol Cs and atomic number 55. It is a highly reactive, silvery-gold alkali metal that is known for its low melting point and is one of the most electropositive and alkaline elements. Cesium is primarily used in atomic clocks, which are among the most accurate timekeeping devices, and in various applications in the fields of chemistry, physics, and telecommunications. Its name is derived from the Latin word “caesius,” meaning “sky blue,” in reference to the bright blue lines in its spectrum.
